Interior Auxiliary Wiring
I am planning to add electronic accessories to the cab of the truck (radios, gauges, switches, etc.) The first thing to do is add additional circuits.
I am using a Blue Sea Systems fuse block, model 5032. This block has 2 groups of 6 circuits each and 12 ground points. I will wire it as 6 switched (with the ignition) and 6 constant power. I could have used 2 smaller blocks and achieved the same thing, but since I had the room, I decided on the single block.
My initial thought was to mount it under the dash. I found 2 problems with that plan - there is not a lot of room to mount a fuse block where you can easily get to it to add wiring, and being upside down while under the dash is not as easy and it used to be...
I decided to the mount the block in the storage bin under the driver's side AC rear seat (which has been removed.) Once a location was picked, I built several wiring harnesses, and routed them through the truck.
Here, you can see the fuse block with the various harnesses attached:
And a close-up of the block:
The single wires in the center of the block are the feeds (source power feeding the block) and the wires on the side are the new circuits.
Wires routed out of storage compartment:
A convenient opening in the structure:
The harness(es) going forward along the door sill:
I had to get bigger grommets...
The fuse block mounted:
I took the constant power from the under hood fuse block instead of directly to the battery. Doing so hides the wire. (I am not on a fused circuit.)
The switched power comes out of the under-dash fuse block. Not my preferred solution, but I really didn't want to pull the entire dash apart to find a switched source.
The second wire here picks up the lights - powered when the lights are on. I will use this for my gauge lights.
Here, you can see the other end of the wiring harness. Each wire is attached to a terminal strip, which is Velcro'ed to the carpet. (Quick and dirty, but it works fine.)
Now, whatever I need power for, I just run a wire to the terminal strip, plug a fuse in the corresponding spot in the block, and I am good to go!